HessenbergTransformer (Hipparchus 3.0 API)

java.lang.Object
- org.hipparchus.linear.HessenbergTransformer

```
public class HessenbergTransformer
extends Object
```
Class transforming a general real matrix to Hessenberg form.
A m × m matrix A can be written as the product of three matrices: A = P × H × P^T with P an orthogonal matrix and H a Hessenberg matrix. Both P and H are m × m matrices.

Transformation to Hessenberg form is often not a goal by itself, but it is an intermediate step in more general decomposition algorithms like eigen decomposition. This class is therefore intended for internal use by the library and is not public. As a consequence of this explicitly limited scope, many methods directly returns references to internal arrays, not copies.

This class is based on the method orthes in class EigenvalueDecomposition from the JAMA library.

See Also:

MathWorld, Householder Transformations

Constructor Summary

Constructors
Constructor Description

HessenbergTransformer(RealMatrix matrix)
Build the transformation to Hessenberg form of a general matrix.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`RealMatrix`	`getH()`	Returns the Hessenberg matrix H of the transform.
`RealMatrix`	`getP()`	Returns the matrix P of the transform.
`RealMatrix`	`getPT()`	Returns the transpose of the matrix P of the transform.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - HessenbergTransformer
```
public HessenbergTransformer(RealMatrix matrix)
```
    Build the transformation to Hessenberg form of a general matrix.
    
    Parameters:
    
    matrix - matrix to transform
    
    Throws:
    
    MathIllegalArgumentException - if the matrix is not square
- Method Detail
  - getP
```
public RealMatrix getP()
```
    Returns the matrix P of the transform.
    P is an orthogonal matrix, i.e. its inverse is also its transpose.
    
    Returns:
    
    the P matrix
  - getPT
```
public RealMatrix getPT()
```
    Returns the transpose of the matrix P of the transform.
    P is an orthogonal matrix, i.e. its inverse is also its transpose.
    
    Returns:
    
    the transpose of the P matrix
  - getH
```
public RealMatrix getH()
```
    Returns the Hessenberg matrix H of the transform.
    
    Returns:
    
    the H matrix